diff --git a/QtScrcpy/device/device.cpp b/QtScrcpy/device/device.cpp
index 15d6414..0f027ea 100644
--- a/QtScrcpy/device/device.cpp
+++ b/QtScrcpy/device/device.cpp
@@ -130,7 +130,7 @@ void Device::initSignals()
 {
     connect(this, &Device::screenshot, this, &Device::onScreenshot);
     connect(this, &Device::showTouch, this, &Device::onShowTouch);
-    connect(this, &Device::setMainControl, this, &Device::onSetMainControl);
+    connect(this, &Device::setControlState, this, &Device::onSetControlState);
     connect(this, &Device::grabCursor, this, &Device::onGrabCursor);
 
     if (m_controller) {
@@ -185,7 +185,7 @@ void Device::initSignals()
                 tips = tr("%1 failed").arg(tipsType);
             }
             qInfo() << tips;
-            if (!m_mainControl) {
+            if (m_controlState == GCS_CLIENT) {
                 return;
             }
             QMessageBox::information(m_videoForm, "QtScrcpy", tips, QMessageBox::Ok);
@@ -280,13 +280,14 @@ void Device::startServer()
     });
 }
 
-void Device::onSetMainControl(Device* device, bool mainControl)
+void Device::onSetControlState(Device* device, Device::GroupControlState state)
 {
     Q_UNUSED(device)
-    if (m_mainControl == mainControl) {
+    if (m_controlState == state) {
         return;
     }
-    m_mainControl = mainControl;
+    m_controlState = state;
+    emit controlStateChange(this, m_controlState);
 }
 
 void Device::onGrabCursor(bool grab)
@@ -294,13 +295,16 @@ void Device::onGrabCursor(bool grab)
     if (!m_videoForm) {
         return;
     }
+    if (m_controlState == GCS_CLIENT) {
+        return;
+    }
     QRect rc = m_videoForm->getGrabCursorRect();
     MouseTap::getInstance()->enableMouseEventTap(rc, grab);
 }
 
-bool Device::mainControl()
+Device::GroupControlState Device::controlState()
 {
-    return m_mainControl;
+    return m_controlState;
 }
 
 bool Device::saveFrame(const AVFrame* frame)
diff --git a/QtScrcpy/device/device.h b/QtScrcpy/device/device.h
index 3a28f37..9a43b91 100644
--- a/QtScrcpy/device/device.h
+++ b/QtScrcpy/device/device.h
@@ -35,6 +35,11 @@ public:
         QString gameScript = "";            // 游戏映射脚本
         bool renderExpiredFrames = false;   // 是否渲染延迟视频帧
     };
+    enum GroupControlState {
+        GCS_FREE = 0,
+        GCS_HOST,
+        GCS_CLIENT,
+    };
     explicit Device(DeviceParams params, QObject *parent = nullptr);
     virtual ~Device();
 
@@ -43,7 +48,7 @@ public:
     const QString &getSerial();
 
     void updateScript(QString script);
-    bool mainControl();
+    Device::GroupControlState controlState();
 
 signals:
     void deviceDisconnect(QString serial);
@@ -75,13 +80,16 @@ signals:
     // self connect signal and slots
     void screenshot();
     void showTouch(bool show);
-    void setMainControl(Device* device, bool mainControl);
+    void setControlState(Device* device, Device::GroupControlState state);
     void grabCursor(bool grab);
 
+    // for notify
+    void controlStateChange(Device* device, Device::GroupControlState state);
+
 public slots:
     void onScreenshot();
     void onShowTouch(bool show);
-    void onSetMainControl(Device* device, bool mainControl);
+    void onSetControlState(Device* device, Device::GroupControlState state);
     void onGrabCursor(bool grab);
 
 private:
@@ -105,7 +113,7 @@ private:
     QTime m_startTimeCount;
     DeviceParams m_params;
 
-    bool m_mainControl = false;
+    GroupControlState m_controlState = GCS_FREE;
 };
 
 #endif // DEVICE_H
diff --git a/QtScrcpy/device/ui/toolform.cpp b/QtScrcpy/device/ui/toolform.cpp
index c21d142..dc7172b 100644
--- a/QtScrcpy/device/ui/toolform.cpp
+++ b/QtScrcpy/device/ui/toolform.cpp
@@ -26,7 +26,11 @@ ToolForm::~ToolForm()
 
 void ToolForm::setDevice(Device *device)
 {
+    if (!device) {
+        return;
+    }
     m_device = device;
+    connect(m_device, &Device::controlStateChange, this, &ToolForm::onControlStateChange);
 }
 
 void ToolForm::initStyle()
@@ -52,10 +56,16 @@ void ToolForm::updateGroupControl()
     if (!m_device) {
         return;
     }
-    if (m_device->mainControl()) {
-        ui->groupControlBtn->setStyleSheet("color: red");
-    } else {
+    switch (m_device->controlState()) {
+    case Device::GroupControlState::GCS_FREE:
         ui->groupControlBtn->setStyleSheet("color: #DCDCDC");
+        break;
+    case Device::GroupControlState::GCS_HOST:
+        ui->groupControlBtn->setStyleSheet("color: red");
+        break;
+    case Device::GroupControlState::GCS_CLIENT:
+        ui->groupControlBtn->setStyleSheet("color: green");
+        break;
     }
 }
 
@@ -196,6 +206,18 @@ void ToolForm::on_groupControlBtn_clicked()
     if (!m_device) {
         return;
     }
-    emit m_device->setMainControl(m_device, !m_device->mainControl());
+    Device::GroupControlState state = m_device->controlState();
+    if (state == Device::GroupControlState::GCS_FREE) {
+        emit m_device->setControlState(m_device, Device::GroupControlState::GCS_HOST);
+    }
+    if (state == Device::GroupControlState::GCS_HOST) {
+        emit m_device->setControlState(m_device, Device::GroupControlState::GCS_FREE);
+    }
+}
+
+void ToolForm::onControlStateChange(Device *device, Device::GroupControlState state)
+{
+    Q_UNUSED(device)
+    Q_UNUSED(state)
     updateGroupControl();
 }
diff --git a/QtScrcpy/device/ui/toolform.h b/QtScrcpy/device/ui/toolform.h
index 28f38c5..1c4d10b 100644
--- a/QtScrcpy/device/ui/toolform.h
+++ b/QtScrcpy/device/ui/toolform.h
@@ -5,6 +5,7 @@
 #include <QPointer>
 
 #include "magneticwidget.h"
+#include "device.h"
 
 namespace Ui {
 class ToolForm;
@@ -44,6 +45,8 @@ private slots:
     void on_touchBtn_clicked();
     void on_groupControlBtn_clicked();
 
+    void onControlStateChange(Device* device, Device::GroupControlState state);
+
 private:
     void initStyle();
     void updateGroupControl();
diff --git a/QtScrcpy/device/ui/videoform.cpp b/QtScrcpy/device/ui/videoform.cpp
index c9d9c40..ea4a2c9 100644
--- a/QtScrcpy/device/ui/videoform.cpp
+++ b/QtScrcpy/device/ui/videoform.cpp
@@ -184,8 +184,8 @@ void VideoForm::updateShowSize(const QSize &newSize)
             showSize.setHeight(showSize.width() / m_widthHeightRatio);
         }
 
-        if (isFullScreen()) {
-            onSwitchFullScreen();
+        if (isFullScreen() && m_device) {
+            emit m_device->switchFullScreen();
         }
         if (m_skin) {
             QMargins m = getMargins(vertical);
@@ -351,13 +351,13 @@ void VideoForm::wheelEvent(QWheelEvent *event)
 
 void VideoForm::keyPressEvent(QKeyEvent *event)
 {
+    if (!m_device) {
+        return;
+    }
     if (Qt::Key_Escape == event->key()
             && !event->isAutoRepeat()
             && isFullScreen()) {
-        onSwitchFullScreen();
-    }
-    if (!m_device) {
-        return;
+        emit m_device->switchFullScreen();
     }
     if (event->key() == Qt::Key_C && (event->modifiers() & Qt::ControlModifier)) {
         emit m_device->requestDeviceClipboard();